Issue 28, 2020

Cyclization step of noradrenaline and adrenaline autoxidation: a quantum chemical study

Abstract

Catecholamine autoxidation has been recognized as one of the potential trigger factors for catecholaminergic neuron loss characteristics of neurodegenerative diseases. The cyclization step with intramolecular Michael addition of catecholamine o-quinones has been shown to be the irreversible and rate limiting step of the autoxidation reaction across a broad pH range and has a complex pH dependence that has not yet been fully understood. Using quantum chemical calculations, we demonstrated that in the case of noradrenaline and adrenaline two catecholamine o-quinone species, one with an unprotonated and one with a protonated quinone group can participate in the cyclization reaction and that the mechanisms of these reactions significantly differ, emphasizing the importance of quinone group protonation states in the reaction mechanism. With a thorough exploration of the reaction kinetics, we further showed that at acidic pH the cyclization reaction rate is pH independent, while at alkaline pH the pH dependence is marked, explaining the experimentally observed complex pH dependence.

Graphical abstract: Cyclization step of noradrenaline and adrenaline autoxidation: a quantum chemical study

Article information

Article type
Paper
Submitted
24 Mär 2020
Accepted
17 Apr 2020
First published
28 Apr 2020
This article is Open Access
Creative Commons BY-NC license

RSC Adv., 2020,10, 16650-16658

Cyclization step of noradrenaline and adrenaline autoxidation: a quantum chemical study

N. Umek, RSC Adv., 2020, 10, 16650 DOI: 10.1039/D0RA02713H

This article is licensed under a Creative Commons Attribution-NonCommercial 3.0 Unported Licence. You can use material from this article in other publications, without requesting further permission from the RSC, provided that the correct acknowledgement is given and it is not used for commercial purposes.

To request permission to reproduce material from this article in a commercial publication, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party commercial publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements